Ammonia → Ammonia

A solution of 2-hydroxy-1-napthoic acid (5.0 g, 26.6 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (5.6 g, 29.2 mmol), and 1-hydroxybenzotriazole (3.95 g, 29.2 mmol) in tetrahydrofuran (70 mL) was stirred at room temperature for 30 minutes prior to the addition of 0.88 ammonia (6 mL). The resulting suspension was stirred at room temperature for 2 hours. The reaction mixture was then filtered, and the filtrate was diluted with water (80 mL) and extracted with ethyl acetate (4×80 mL). The combined organic extracts were washed with water (2×50 mL) and brine (50 mL), dried over sodium sulfate and concentrated in vacuo to give an orange oil. Purification of the oil by column chromatography on silica gel, eluting with dichloromethane:methanol:0.880 ammonia, 95:5:0.5, afforded the title compound as a pink solid in 37% yield, 1.83 g. 1HNMR (400 MHz, CDCl3) δ: 6.11-6.35 (2H, bs), 7.17 (1H, d), 7.36 (1H, dd), 7.54 (1H, dd), 7.79 (1H, d), 7.84 (1H, d), 8.22 (1H, d), 11.70-11.88 (1H, bs); LRMS ESI m/z 186 [M−H]−

1. filtrationThe reaction mixture was then filtered
2. additionthe filtrate was diluted with water (80 mL)
3. extractionextracted with ethyl acetate (4×80 mL)
4. washThe combined organic extracts were washed with water (2×50 mL) and brine (50 mL)
5. dry with materialdried over sodium sulfate
6. concentrationconcentrated in vacuo
7. customto give an orange oil
8. customPurification of the oil by column chromatography on silica gel
9. washeluting with dichloromethane

ORD record

ord-c654d0d0bcf74e1f8ced50cfe3a7525b

Source dataset

uspto-grants-2009_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07547731B2